Nurses Rejected Safer IV Tubing—Even When It Could Save Lives

The 2018 simulation at Johns Hopkins Hospital was cleanly designed. Researchers gave ICU nurses two different IV line setups—one with standard transparent tubing, one with color-coded lines matching their ports—and measured error rates under timed, high-stress scenarios. The color-coded system produced fewer mistakes. Fewer misconnections. Fewer moments where a nurse reaching for an epidural line grabs an arterial line instead, with all the bleeding risk that entails. Then the researchers asked the nurses whether they wanted to keep using the color-coded system. The overwhelming majority said no. This is the puzzle that keeps patient-safety advocates awake. A simple, low-cost intervention—color-coding tubing by function—has existed for years. Standards bodies have published guidelines for it. The Joint Commission has flagged misconnections as a persistent hazard. Yet most hospitals still use the same visually ambiguous clear tubing they used in the 1990s. The technology is not the barrier. The cost of printing colored plastic is negligible. The barrier is that the people who would have to retrain—the nurses, the anesthesiologists, the respiratory therapists—already know the old system. What the Hopkins study captured is a textbook case of the endowment effect in a high-stakes setting. The nurses had invested years building mental maps of the existing tubing: the way a particular connector feels in the hand, the subtle differences in port shape, the muscle memory of tracing a line from pump to patient. That knowledge is not trivial. In a code blue, with the patient crashing and four different infusions running, that cognitive map is survival equipment. The color-coded system asked them to abandon it. Even though the new map was objectively easier to read, the old one was theirs. They had earned it through repetition. Giving it up felt like a loss, not a gain. This is the standard story of why better tools fail to diffuse. The common belief is that safer systems are always adopted once proven effective. The evidence suggests otherwise. What matters is not the objective improvement in safety but the subjective experience of switching costs for the people who have to change their habits. The nurses were not irrational. They were correctly valuing the fluency they had built over years, even though that fluency came at the cost of a higher baseline error rate. The implication for hospital leadership is uncomfortable. You cannot simply demonstrate that a new system is safer and expect adoption. The endowment effect means that the incumbent system is always overvalued by the people who use it. The only reliable path is to force the change, absorb the temporary productivity loss, and invest in the retraining that makes the new system feel familiar. That means removing the old tubing from inventory. Running mandatory simulation drills. Accepting a dip in throughput for the first three months. The alternative—leaving adoption to individual choice—guarantees that the safer system stays on the shelf. The Hopkins nurses eventually did switch, after the hospital made the color-coded tubing the only option. Error rates dropped. Complaints faded. But the sequence matters: demonstration of benefit was not enough. The change had to be mandated. The lesson is not that nurses are stubborn. It is that the endowment effect is stronger than evidence, and that overcoming it requires institutional force, not persuasion.